https://communities.sas.com/t5/SAS-Programming/first-id-and-last-id/m-p/309501#M66605 thank you for clearing my doubt.:-) Sat, 05 Nov 2016 11:54:45 GMT ROHINISDAS 2016-11-05T11:54:45Z https://communities.sas.com/t5/SAS-Programming/first-id-and-last-id/m-p/309497#M66601 <P><IMG src="https://communities.sas.com/t5/image/serverpage/image-id/5672i56C2E3C5AE3201DF/image-size/original?v=v2&amp;px=-1" border="0" alt="error.PNG" title="error.PNG" /></P><P>&nbsp;</P><P>please explain me the error formed?</P><P>&nbsp;</P> Sat, 05 Nov 2016 11:00:41 GMT https://communities.sas.com/t5/SAS-Programming/first-id-and-last-id/m-p/309497#M66601 ROHINISDAS 2016-11-05T11:00:41Z https://communities.sas.com/t5/SAS-Programming/first-id-and-last-id/m-p/309498#M66602 Whenever you are using the BY statement the source data need to be sorted in the same way as specified in the BY statement. <BR />Exception: when the data is stored in SPDE, SPDS or an external RDBMS the sorcerer engine sorts the data on the fly based on your BY statement. Sat, 05 Nov 2016 11:17:43 GMT https://communities.sas.com/t5/SAS-Programming/first-id-and-last-id/m-p/309498#M66602 LinusH 2016-11-05T11:17:43Z https://communities.sas.com/t5/SAS-Programming/first-id-and-last-id/m-p/309501#M66605 thank you for clearing my doubt.:-) Sat, 05 Nov 2016 11:54:45 GMT https://communities.sas.com/t5/SAS-Programming/first-id-and-last-id/m-p/309501#M66605 ROHINISDAS 2016-11-05T11:54:45Z